Contact element



Patented Apr. 15,, 1947 nane con'mcr nrlnlvrnnr Philip L. Alger, Schenectady, N. Y assignor to General Electric iConipany, a corporatien at New York No Drawing. Application @ctober a, rate,

Serial No. 505,535

1 Claim. l

My invention relates to contact elements and particularly to such elements as are used with electrical apparatus as current collecting brushes.

An object of my invention is to provide an improved electrical contact element.

A further object of my invention is to provide an improved electri: current collector contact element including a carbonaceous material and provided with an inorganic lubricant. for the contact surface thereof.

Further objects and advantages'of my inventlon will become apparent and my invention will be better understood from the following description, and the features of'novelty which characterize my invention will be pointed out in the claims annexed to and forming a part of this specification.

It has been found that under normal atmospheris conditions with average humidity atmospheric water vapor and oxygen together provide one of the'best known lubricants for the contact surfaces-of carbon and metal-graphite brushes and similar bearing surfaces. It also has been found that electrical contact elements made of porous blocks of finely divided electrically conductive material such as carbon or metal-graphite brushes tend to wear away very rapidly in dry or rarefied atmospheres.

I have found that a relatively movable contact element such as might be used for an electrical brush contact or a relatively movable bearing element for contact with another member, such as a, rotating slip ring or commutator, will have a relatively long wearing life when it is made of a graphitic or carbonaceous material intimately combined with a metaland a metallic sulphide of a metal having a lower melting point that the ill- 325) en) ture of finely divided powders of graphitic material with a metal of high electrical conductivity, such as copper, and a lower melting point metallic sulphide, such as a sulphide of silver, cadmium, molybdenum, zinc, lead, etc, provides a par= ticularly desirable combination.

I have found that this type of electrical brush contact element is preferably formed of a block of carbonaceous material such as finely divided graphite, a metal such as finely divided copper, and a metallic sulphide such as silver sulphide. In some instances, the sulphide may be formed during the manufacturing process by adding powdered sulphur and silver or other lower melt-= ing point metal to a mixture of graphite and pow dered metal, such as copper, having a higher melting point, mixing, heating, and pressing the mixture together and thereby forming a metal lic sulphide mixed with graphite and metal.

While I have described particular embodiments of my invention, modifications thereof will cc cur to those skilled in the art, and I desire it to be understood, therefore, that my invention is not to be limited to the particular arrangements disclosed, and I intend in the appended claim to cover all modifications which do not depart from thespirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

A brush contact element including a block formed of a finely divided carbonaceous material, finely divided copper, and cadmium sulphide.

PHILIP L. ALGER.

CITED UNETED STATES PAWNTS Name Date Whitney Dec. 22, 191% Number 

